1. Field
The following description relates to a method of detecting a change in an object and apparatuses for performing the method.
2. Description of Related Art
To acquire biosignal information, for example, a heart rate or a respiratory rate, from an outside of a body, a technology using a near field may be used. The technology includes a scheme of detecting a change in a magnitude of an output signal based on a frequency characteristic of a filter and calculating a heart rate and a respiratory rate when an oscillation frequency changes due to a change in a characteristic of a resonant frequency of a resonator of an oscillator in response to a change in a body tissue in a near electromagnetic field of the resonator.
However, the scheme requires an oscillation circuit and a high quality filter to convert a change in the resonant frequency of the resonator to a change in a magnitude of a signal, and frequency characteristics of the resonator, the oscillation circuit, and the filter need to be well matched.